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virtio: Use spin_lock_irqsave/restore for virtio-pci 

virtio-pci acquires its spin lock in an interrupt context so it's necessary
to use spin_lock_irqsave/restore variants.  This patch fixes guest SMP when
using virtio devices in KVM.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Anthony Liguori 2008-03-02 16:37:48 -06:00 committed by Rusty Russell
parent a978b30af3
commit 27ebe308af
1 changed files with 9 additions and 6 deletions
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15
drivers/virtio/virtio_pci.c
View File

@ -177,6 +177,7 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
struct virtio_pci_device *vp_dev = opaque;
struct virtio_pci_vq_info *info;
irqreturn_t ret = IRQ_NONE;
unsigned long flags;
u8 isr;
/* reading the ISR has the effect of also clearing it so it's very
@ -197,12 +198,12 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
drv->config_changed(&vp_dev->vdev);
}
spin_lock(&vp_dev->lock);
spin_lock_irqsave(&vp_dev->lock, flags);
list_for_each_entry(info, &vp_dev->virtqueues, node) {
if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
ret = IRQ_HANDLED;
}
spin_unlock(&vp_dev->lock);
spin_unlock_irqrestore(&vp_dev->lock, flags);
return ret;
}
@ -214,6 +215,7 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtio_pci_vq_info *info;
struct virtqueue *vq;
unsigned long flags;
u16 num;
int err;
@ -255,9 +257,9 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
vq->priv = info;
info->vq = vq;
spin_lock(&vp_dev->lock);
spin_lock_irqsave(&vp_dev->lock, flags);
list_add(&info->node, &vp_dev->virtqueues);
spin_unlock(&vp_dev->lock);
spin_unlock_irqrestore(&vp_dev->lock, flags);
return vq;
@ -274,10 +276,11 @@ static void vp_del_vq(struct virtqueue *vq)
{
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
struct virtio_pci_vq_info *info = vq->priv;
unsigned long flags;
spin_lock(&vp_dev->lock);
spin_lock_irqsave(&vp_dev->lock, flags);
list_del(&info->node);
spin_unlock(&vp_dev->lock);
spin_unlock_irqrestore(&vp_dev->lock, flags);
vring_del_virtqueue(vq);